Multiple reflector for lighting units



Feb. 20, 1945. E. a 'HAL M N ET AL 2,369,894

MULTIPLE REFLECTOR FOR LIGHTING UNITS Filed Oct. 22, 1941 4 Sheets-Sheet 1 Q i 1 '-w I Mentor- E I ERIC B-HPaLLMhN. CHARLES cwanv 11 I} cnnzu-zs H-MaGOuGl-LJR. Wiiorng Feb. 20, W45. E. s. HALLMAN ET AL.

MULTIPLE REFLECTOR FOR LIGHTING UNITS Filed Oct. 22, 1941 4 Sheets-Sheet 2 Eas B HAM-MAN CHfiEkES QWEAYER. yLES n- MGGOUGHHJR.

' Feb. 20, 1945. E. B. HALLMAN ET AL 293599394 MULTIPLE REFLECTOR FOR LIGHTING UNITS Filed Oct. '22, 1941 4 Sheets-Sheet :s

- Ems B- HHLLMBN HHR ES awe/ave?- c neLEs Pa- MGousH,dR.

Feb. 20, 1945. E. B. HALLMA N ET AL 21,359,394

MULTIPLE REFLECTOR FOR LIGHTING UNITS Filed Oct. 22, 1941 4 Sheets-Sheet 4 I E21:- 3 HHLl-MBN CHARLES -WEAVER tending diagonally of Patented Feb. 20, 1945 -uNiT :-;o sTArEs PATENTYOF'VFICE Eric B. Hallman, Conshohocken, and Charles C.

Weaver and Charles A. McGough, Jr., Philadelpl iia, Pa., assignors to Electric Service Supplies Company, Philadelphia, Pa., a corporation of Pennsylvania .Application October 22,

1941, Serial No. 416,030

3'Claims. (o1. zen-7.35)

This invention relates to lightingfixtures and more particularly to improvements in the design and construction of reflectors such as ar employedin vehicle interior lighting fixtures.

Among the principal objects. of thepresent invention is to provide a vehicle lighting fixture with a single reflector of such character, as will produce, from a single source of light, a plurality of directionally controlledbeams of light, each of sufiicient intensity to insure adequateilluminabeing understood that tion at and throughout theseveral reading zones respectively illuminated by the said beams-of light.

Heretofore and prior to the present invention,

vehicle interior lighting has involved either the use of I a plurality of separate. lighting units spaced in the vehicle to provide for general illumination without regard to the individual spacing of the passenger, seats, or the use of separate lighting units designed to spot light two or more adjacentreading zones. Throughout this specification and in the claims appended hereto, the term adjacent reading zones is employed to mean the reading planes of a pair of laterally disposed or side-,by-side seatsof a two-passenger cross-seat; the reading planes'of apair of successive aisle or window seats arranged in tandem,

i. e., longitudinally of the vehicle; or the reading planes of a pair of seats laterally and longitudinally spaced from each other to the extent of a single seat, the readingplanes in this last instance beingspaced from each other; in a. direction ex the longitudinal axis of the vehicle. J

The present invention, contemplates notonly the use of a lighting unit having a single, source of light to illuminate a pair'of adjacent reading zones, but also the provision of special reflector means insuch lighting unit to project separate and independent beams oflight emanating' from 'senger vehicle showing various typical from a single source for illuminating twoor more adjacent reading zones. 1 Other objects and advantages of the present invention will appear more fully hereinafter, it

the present invention consists in the combination, construction, location and relative arrangement of parts, all as will be described in detail hereinafter, as shown in the accompanying drawings and as finally pointed out in the appended claims.

In the accompanying drawings, which illustrate several different embodiments of the present invention.

Figure 1 is a plan view of the interior of a passeating arrangements each involvingtwo or more separate reading zones which may be illuminated by single lighting fixtures of the present invention;

Figure 2 is a plan view of a reflector unit constructed in accordance with the principles of the present invention for projecting three separate .beams of light from a single light source;

such single light source to adequately illuminate I each of the adjacent reading zones. a

More specifically it is an object of the present invention to provide in a. singlelighting unit a composite reflector made up of a plurality of parabolic reflector sections having the .same or difierent focal lengths, said reflector sections being so related that their focal points 'are' brought into substantial coincidence, in consequence of which the; composite reflector projects,

from a single source of light located at thecommon focal point oithe several reflector sections,

separate beams of light, the axes of which are angularly related toeach other. n Thus, the composite reflector of the present invention provides Figures 3 and 4 are sectional views taken on the v lines 3-3 and 4-4 of Figure 2; I

Figures 5 and 6 are diagrammatic views illustrating the principles involved in the construction of the reflector of Figure 2;

Figures 18 and 19 are sectional views taken on the lines I8l8 and l9-I9 of Figure 17;

Figures 20 and 21 are sectional views taken on lines 20-40 and 2I-2l of Figure 17; and I ,Figures 22, 23, 24 and 25 are diagrammat c views illustrative of the reflector unit of Figure sov 17. v Referring now to the drawings and more particularly to Figure 1 thereof which illustrates'a I arrangement in an automotive typical seating passenger Vehicle, it will be observed that this seating arrangement includes at least four dif- Figure 7 is a plan view of a two-beam reflector 7 unit;

ferent groupings of passenger seats, each of which groupings is adapted to be illuminated by a single lighting fixture of the present invention. Thus, seat grouping A includes a longitudinal seat for two' passengers having adjacent reading zones disposed side by side, while seat "grouping B includes a cross-seat for two passengers having 'a pair of side by side adjacent reading zones. Seat grouping 0 includes a longitudinal seat for three passengers having three adjoining reading zones,

and seat grouping D includes a pair of cross-seats arranged in tandem to provide aseating arrangement for four passengers, each passenger seat having, of course, a separate reading zone. In

each seat grouping, the approximate position of s the overhead single lighting unit as employed and constructed in accordance with the principles of the present invention is designated by thereforence character 0:, it being further noted that while in the case of each of the seat groupings A and C the lighting unit is located almost directly above the center of the seating zones to be illuminated,

inthe case of the seat grouping B the "lighting Figures 17 to 21.

Considering first the lighting unit for the simplest multiple seating arrangement as represented by the seat rouping A'in Figure 1,'reference is had to Figures 12 to 14 wherein the reflector section a-d and the parabola section b-e are so relatedthat their respective focal axes 0-) and c intersect one another at the focal point for the'simple parabola 1:. When two such para- 'bolic sections have been obtained, they are joined together'inthev relation just described and their free edges are trimmed and out-turned to provide a radially extending supporting rim [2. In actual unit of the present invention includes, as shown,

a reflector ill in the form of a'sheet metal'stamping having a central concavedportion I l bounded by a-flat marginal rim l2. The sections ofthe concaved reflecting portion ll of the reflector taken in the transverse planes of lines l3--|3 'for a purpose which will be'apparent hereinafter.

It will be observed that whereas in its transverse section of Figure 14' the shape of th reflector H is that of a simple parabola having a predetermined focallength and fixed focal point 13, in its transverse section ofFigure 13 the reflector shape has been changed from this simple parabolic contour and instea'dis composed of a pair of similar parabolic sections 13* and 13 the focal axes of each of which has been swung about the common focal point l3 to provide the reflector with a peak orridgell extending transversely thereof along the line I l-l4 of Figure 12.

Figures 15 and 16 illustrate diagrammatically the principles involvedin obtaining the reflector ll having the'transve'rse section shown in Figure 1'3.

Referringpnow toFigures "15 and 16,it' willbe observed that the parabolic section [3 of the reflector H is derived by severingthe simpleparabolic section 71 along the transverse plane of the line. f'--d to providers, parabolic section a-d which is swung "about the transverse axis of the 'focal point f through a predetermined angle '6. g-- so as to present the point d at the focal axis of thesimplepara'bolap. Similarly, the

zones to be illuminated.

manufacture, of course, the parabolic sections so joined together are employed as a form in the production of suitable dies from which reflectors of the character shown in Figures 12 to 14 may be stamped out uniformly andin quantities as desired.

The reflector] I so formed is then provided with a suitable lamp socket l4 Ior'receiving a lamp [5, the source of light of which-is disposed substantially'at the focal point of'the reflector. As most clearly appears in Figure 16, the reflector II, by reason-of its pair of reflecting sections Ili -and l3 'each of parabolic form, projects a pair of intersecting light beams from the single source of light, the rays of one light beam paralleling the focal axis 0-) of the reflector section (1-12 and thoseof the otherlight beam paralleling "the focal axis of the reflector section be.

The reflector ll is, of course, mounted in a suitable housing therefor (not shown), as, for example, in a'lens-equipped casing of the type shown in UnitedStates Letters Patent No. 2,249,- '357,-granted July 15, 1941, to Herbert J. Graham, to thereby complete the lightin unit, and when such unit is employed to illuminate a seat group- 'ing such as that designated A in Figure 1, the two beams projected from the unit respectively illuminate the'two reading zones of the seat grouping A. Obviously, by varying the angle of rotation of the reflector sections a-d and b-'-e about the transverse axis of the focal point I, the angular relation of the projected beams may be changed as desired. It will'be apparent that in order to secure proper and adequate illumination of the reading zones of seat grouping A (see Figure 1), it is-necessary to vary the angular relation of the projected beams to compensate for variations in the height of the lighting fixture above said reading zones. Inasmuch as the lighting fixtures in passenger vehicles are usually mounted upon the ceiling, the height of the fixture above'the reading planes is fixed and the angular relation of the projected beams is accordingly predetermined to insure projection of the crossed beams respectively upon the reading It will be noted in connection with thelighting fixture of Figures 12 to 14 that it is designed to project thelbeams downwardly in such manner "that their central axes are disposed substantially versesection taken on the line l4-l'4 of Figure 12. In the seat grouping-A such lateral deviation or directional adiustmentorthe projected beams .is unnecessary because the lighting unit ismountluminated.

However, in the case of seat grouping B, it will be noted that the lightingunit is disposedabove the back of the cross-seat, i. e., somewhat to'the rear of the center of-the reading zones to be'illuminated. In such case, a lighting fixture is employed having the reflector unit of Figures '7'to 9.

This latter unit is constructed similarlyto that of Figures 12 to 14 in thatit also is provided with a central concaved reflector part It which is composed of a pair of identical parabolic reflector sections I! and [1 which are derived from simple parabolic shapes and merged in the transverse plane of reflector extending along the line 88 of Figure 12, the focal points of these reflector sections W and I! being coincident, asat l8. v

The beams of light respectively projectedfrom these sections I! and I1? are shown in Figure 11 wherein it will be noted that they are angularly related to the extent predetermined by the angles through which said sections are swung about the transverse axis of the focal point (e. g.10) I In order to impart a directional characteristic to the angularly related beams respectively projected from the parabolic sections I! and 11!? of the reflector, the latter as a whole is rotated through a predetermined angle (e. g.-22) about the axis of the focal point l8 extending transversely of the line 8+8 of Figure '7. The focal axis of the parabolic line of mergence of thesections l'l and I1 is thus angularly related to the vertical (see Figure 8), in consequence of which I the two beams respectively projected by the reflector sections 1 l and HP not only intersect one another below the focal point l8 of the reflector,

but also are disposed with their central axes dis-- posed commonly in a plane inclined with respect to the vertical. Thus, when the lighting unit as designed for application to the seat grouping B of Figure 1 is mounted above and somewhat to the rear of the reading Zones, the two beams projected therefrom will be forwardly directed and will intersect one another to respectively illuminate the two reading zones arranged in side side relation. I 4 V The reflector unit constructed in accordance with the principles of the present invention and designed for application to a seat'grouping C. which includes three adjoining seats and a cor responding number of reading zones arranged in side by side relation, is shown in Figures 2 to 4, inclusive. Referring now 'moreparticularly to these latter figures, it will be observed that the reflector l8 is provided with a central concaved reflecting part l9 and a flat marginal supporting rim 20. The central concaved reflecting? part IQ of the reflector is composed of three separate parabolic sections 20 20 and 20. The parabolic sections 2|] and 20 are counterparts-of one another and are laterally spaced apart to embrace therebetween the intermediate reflecting' 'section 20, the meeting edges of the several parabolic sections of the reflector being smoo-thly'merged I at the common focal point 25 of the reflector.

Figures 15 and 6 illustrate the principles involved in the construction of the reflectorlunit 'of Figures 2 to 4. As shownin these Figures 5 and 6; the laterally spaced reflector sections 2i] and 20 are obtained by splitting a simple parabolic reflector p, as shown in Figure 5, along thetra'nsverse plane of the focal axis cf. The two halves of the parabolic reflector are then oppositely rotated about a transverse axis extending through the focal point, f through predetermined angles (e. g.-23). Thereupon a separate parabolic section is fitted between theproximate edges of the separated reflector sections, the intermediate reflector section selected forthis-purpose being of parabolic form and of such focal length that its focal point coincides with the common focal point of the'separated reflector sections; In the particular illustration shown in Figures 2 to 6, the reflector sections 2!! and Zll are each of 5% inch focal length, while the intermediate para-- bolic sections is of -}-t inch focal length, it having been found thatparabolic sections of such focal lengths 'may be smoothly related to form a multiple reflector unit having a common focal point as shown.

It will-beunderstood, of course, that in the case of the reflector unit shown in Figures.2 to 3, as in the case of all of the reflector units described in this specification, the several parabolic sections'which go to make up the complete for the projection of three separate beams of light, the beams emmanating from the reflector sections 20 and 20 being angularly related so asvto cross one another below the focal point of the reflectorfor illuminating the reading zones of the outermost seats of the seat grouping C. The-intermediate reflector section 20 projects a third beam downwardly through the focal point of the reflector to illuminate the reading zone ell) together along the lines 2| and 22, as appears the intermediate parabolic-section 20 is of a dif- 7 6 of'the central seat of said grouping. As in the case of the lighting unit of Figures 12 to 14 for use in illuminating the seat grouping A, the three beams projected by the reflector unit of Figures 2 to l do not deviate frontally or rearwardly of the jseatC. Instead, all of the beams are disposed so that their central axes lie substantially in a vertical plane extending through the common longitudinal center line of the seats C. Of

course, if it is desired to impart a directional the reflector unit, all that would be necessary in such case would be to rotate the unit as a whole through a predetermined angle about a horiz0nital axis extending transversely along the line 3--73 of Figure 2 and through. the focal point 25 of the reflector unit. In other words, a directionalcharacteristic may be imparted to the three beams of the reflector unit in the same manner as such directionalcharacteristic was imparted to the twobeam,reflector unit of Fisures 7 to '9.

Finally, for application to a seat grouping such as 'D shown in Figure 1, which includes as many as four separate reading zones, the reflector unit of Figures 17 to 20 may be employed. This latter unit consists of a central concaved reflecting part26 having a flat marginal rim 21, the central concaved part 26 being composed of four separate parabolic sections 28 28. 28 and 28 These four parabolic sections are derived as'in the previously described forms from'simple parabolic reflectors of such focal lengths that when said sections are assembled and merged together as shown in Figures -1'7-to 21, their several focal points coincide atthe point 29. As in the former cases, the reflector is provided with a lamp socket 30 for receiving a lamp 3|, the said lamp and'lamp socket being so operatively associated with the reflector that the filament of the lamp is located substantially at the focal point 29 of the reflector.

The reflector unit of Figures 17, et. seq., projects four separate beams of light which are so angularly related that they intersect one another at a point below the focalpoint 29 of the reflector and in effect spot light each of the four reading zones of the seat grouping D. In this connection, it will be noted that the beams of light projected from the reflector sections 28 and 28 intersect one another in a plane extending transversely of the reflector unit along'the line 20-20 of Figure 17, while the beams of light projected from the reflector sections 28 and 28 intersect one another in a transverse plane extending through the reflector along the line 2I-- 2| of Figure 17. Thus, beams of light projected from the reflector sections 428* and 28 are employed to illuminate one pair of diagonally spaced reading zones in the seat grouping D, While the beams of light projected by reflector sections 28 and 28 illuminate the other pair of diagonally spaced reading zones in said seat grouping.

Figures 22 to 25, inclusive, illustrate diagrammatically the manner in which the several reflector sections of the multiple reflector 26 are derived and corelated to form the complete refiector unit. Figures 22 and 23 illustrate the formation of the transverse section of the reflector unit as shown in Figure 18, while Figures 24 and 25 illustrate .the formation of the transverse section as shownin Figure 19.

The reflector sections 28, 28 28 and '28 are each derived in similar manner from simple parabolic reflectors p of suitable focal length as rep- 9.

from the reflector p in such manner that one I radially extending edge of the sector lies in that transverse plane of the line fd of Figure 22 which extends through the point a, while the other radially extendingedge of the sector lies in that transverse plane of th line fd extending through the point a.

The second section 28 is similarly obtained by cutting a sector from an identical reflector P,

but this latter reflector i in this case bounded by a radial edge lyingin that transverse plane Ill of the line f-b of the Figure-'22 which extends through the point af, and by an opposite radial edge lying in that transverse plane of the line f-b which extends through the point e.

The third section 28 is obtained by cutting a sector from a parabolic reflector p in such manner that this reflector is bounded on one side by a radial edge lying in that transverse plane of the line fd of Figure 24 which extends through the point e, and on the other side by a radial edge lying in that transverse plane of the line f-d .which extendsthrough the point a.

The fourth section 28 is likewise obtained from a parabolic reflector p by cutting therefrom a sector which is bounded on one side by a radial edge lying in that transverse plane of the line fb of Figure24 which extends through the point e,

and on the other side by a radial edg lying in that transverse plane of the line f-b extending through the point e.

' The four parabolic sectors so derived from the basic parabolic reflectors p are then assembled in relation to eachother to provide the fo-rm'from which is produced the multiple reflector unit shown in Figures 17 to 21, the proximate radial edges of the several parabolic sectors being smoothly merged together and joined along the peak or ridge lines 32, 33, 34 and 35, shown most clearly in Figure 17. In this assembly, it will be observed that each of the reflector sectors have to said line, the two halves of the reflector disposed toeitherside of the transverse line 12+! of Figure 17 are not symmetrical. In other words, whereas the vertical plane of the lighting unit taken along the line l9l9 of Figure 17 substantially bisects the angle of divergence of the beams .projected from either side of said'plane, the beams respectively projected from either side of the transverse vertical plane of the unit taken along the line l8-l8 of Figure 17 intersect said latter plane at unequal angles and thus partake of a directional characteristic. More simply stated with reference to the seat grouping D of Figure 1,

the beams of light respectively projected from the reflector sections 28 and 28 each form angles of 20 forwardly and rearwardly of the focal axis of the reflector and 18 laterally of said axis so as to illuminate the reading zones of the longitudinally spaced aisle seats of the seat grouping D. On the other hand, the beams of light respectively projected from the reflect-or sections 28 'and 28 :each form angles of 0 forwardly and rearwardly with respect to the focal-axis of the unit and only 8 laterally of said axis so as-toproperly illuminate the reading zones of the longitudinally spaced window seats of said seat grouping D. Of

:course, this angular relation between the four beams of the reflector unit may be varied as desired depending upon the relative position of the seats to be illuminated and the mounting :position of the lighting unit in the vehicle and it is not intended to limit this invention to any particular angular relation of the beams.

As has been previously'indicated, all of the referred to.

preferred form the reflector unit'of the present invention is provided with a marginal support ing rim, such reflector may be mounted in the lighting unit of said Patent No. 2,249,357 in the manner'and by the means therein described.

other at a locus below said common focal point torespectively spot-light simultaneously and with substantially. equal intensity the several contiguous reading zones of the seat grouping '5 when said fixture. is mounted above said seat However, any other suitable arrangement may be employed for housing the multiple reflector unit'of the presen'tinvention and it will be un- "derstood further'that the reflector unit hereof may be modified indifferent respects, as by changing the number and relative arrangement of the several component reflector sections thereof, without departing from the general,

principles of the present invention. Itis accordingly intended "to claim the present invention broadly, as 'well as specifically, as indicated 7 in the appended claims.

What is claimed as newanduseful is:

1. In an interior lighting system for a passenger vehicle having a seat grouping consisting of at least three contiguous passenger seats and corresponding reading zones to be illumi-' nated, a unitary lighting fixture mounted above a seat grouping tobe illuminated, said lighting unit being characterized in thatit includes multiple-element reflector associated therewith for projecting a plurality "of independent intersecting light beams of substantially equal in-,

tensity corresponding in number with the number of reading zones to be illuminated, said reprojected from the reflector intersect one an-,

grouping. I v

2. In an interior lighting system for passenger vehicles asdefined in claim 1 wherein said seat grouping includes three seats arranged in closely. spaced sideeby-side' relation and said unitary reflector includes three parabolic sections adapted to project directionally controlled light beams, the axesof which intersect below the common focal point of the reflector and lie in a .commonplane extending at an angle to the vertical whereby, upon mounting said lighting fixture above saidseat grouping and somewhat to the rear of the center of the reading zones thereof, the reading zones of the said three seats are respectively illuminated by-said lightbeams v passing in front ofthe eyes of the seat occupants from a point above the backs of their heads.

3. In an interior lighting system for passenger vehicles as defined in claim 1 wherein said seat grouping includes four seats arranged in closely spaced relation and said unitary reflector ineludes four parabolic sections adapted to project I flector so cut as to provide each section with a a single light source and a relatively shallow A directionallycontrolled intersecting light beams, the axes'of which intersect below the common focal'point of the reflector, said parabolic sections being all characterized in that they are each derived from an identical parabolic r epair of terminal extremities spaced substantially ninety degrees apart in the, horizontal plane of the free marginal edge of the reflector and with athird terminal extremity spaced above said planein such relation to said pair of terminal extremities that lines respectively drawn from said third terminal extremity and from either of said pair of terminal extremities to intersect at the focal point of the'parabolic section form an angle greater than ninety degrees, the third terminal extremities of the several reflector sections being smoothly merged together at a point spaced from said common focal point a distanc greater than the focal length ofany one parabolic section. 

